Electrochemical sensors are known, for example, from the Automotive Electronics Handbook (1994), chapter 6, Wiedenmann et al., xe2x80x9cExhaust Gas Sensorsxe2x80x9d, for use in analyzing exhaust gas of internal combustion engines. Such sensors include a planar sensor element, which is manufactured by the printing ceramic foils onto it, which have electrodes, by laminating the planar sensor element together using a compression force applied by means of a compression pad, and by sintering it. In the case of these sensor elements, there is, however, the danger of the electrode adjacent to the one gas channel being partially or completely severed during lamination, by the use of the compression force, so that normal use is impaired or excluded.
In comparison with the related art, the electrochemical sensor of the present invention has the advantage of ensuring to the greatest possible extent, that the electrode or the electrode leads are routed continuously, without being pinched or broken, even in a transition region between the gas channel and adjacent solid electrolyte foils.
By selecting a suitable layer pattern in the transition region of the electrode, the electrode present in the laminating process in the form of a paste is subjected to a lower pressure, so that the pinching of the electrode in the clamped (squeezed) region and the transport of the electrode into the open region are prevented to the greatest possible extent. Therefore, a reduction in the cross-sectional area of the electrode in the transition region, or even a complete separation of the electrode, is prevented, which means that a lower production variance is achieved, e.g. with regard to the electrical resistance of the electrode, and less manufacturing waste is generated.
The method of the present invention for manufacturing an electrochemical sensor ensures that a lower local pressure is applied to the electrode while laminating it together, and therefore, that the electrode is produced in a manner allowing it to be unpinched and unbroken to the greatest possible extent.